044
FXUS65 KBYZ 171225
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
625 AM MDT FRI JUL 17 2026
KEY MESSAGES
- SCATTERED THUNDERSTORMS AGAIN TODAY. THE MAIN THREAT IS
TORRENTIAL RAIN. MARGINAL CHANCE OF SEVERE THUNDERSTORMS FROM
BILLINGS WEST.
- MARGINAL RISK (LEVEL 1/4) OF FLASH FLOODING OVER PORTIONS OF
CENTRAL AND WESTERN MONTANA TODAY.
- DAILY CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH NEXT WEEK WITH
HIGH TEMPERATURES IN THE 80S AND 90S, WARMEST THIS WEEKEND.
DISCUSSION
TODAY THROUGH THURSDAY...
TODAY WILL SEE UPPER LEVEL RIDGING BEGIN TO BUILD OVER THE CENTRAL
ROCKIES BRINGING HIGHER HEIGHTS INTO MONTANA. MONSOONAL FLOW WILL
CONTINUE TO BRING MUCH ABOVE MOISTURE INTO THE REGION WITH PWATS
AROUND 200% OF NORMAL. THESE INGREDIENTS BRING A 20-50% CHANCE
FOR THUNDERSTORMS STARTING THIS AFTERNOON. DECREASED SHEAR VALUES
DUE TO BUILDING HEIGHTS WILL LIMIT SEVERE STORM POTENTIAL. SLOW
MOVING STORMS WITH HIGH MOISTURE CONTENT MEANS TORRENTIAL RAIN
WILL BE THE BIGGEST THREAT WITH THESE STORMS. THE WEATHER
PREDICTION CENTER HAS ISSUED A LEVEL 1 OF 4 RISK FOR EXCESSIVE
RAINFALL FOR AREAS WEST OF BILLINGS.
UPPER LEVEL RIDGING PEAKS SATURDAY INCREASING TEMPERATURES INTO
THE MID TO HIGH 90S F. SCATTERED SHOWERS AND GENERAL
THUNDERSTORMS ARE EXPECTED TO BRING THE POTENTIAL FOR TORRENTIAL
RAIN. THE WEATHER PREDICTION CENTER HAS ISSUED A LEVEL 1 OF 4 RISK
FOR EXCESSIVE RAINFALL FOR LOCATIONS SOUTHWEST OF BILLINGS. SUNDAY
AND MONDAY SEE AN UPPER LEVEL WAVE DEPRESS THE UPPER LEVEL RIDGE.
DOWNSLOPING 700 MB WINDS SUNDAY WILL KEEP TEMPERATURES ABOVE
AVERAGE IN THE MID TO HIGH 90S F. THIS PATTERN WILL PUSH THE
ANOMALOUSLY HIGH MOISTURE FURTHER TO THE SOUTH KEEPING IT OUT OF
MONTANA. PRECIPITATION CHANCES ARE EXPECTED TO BE CONFINED TO THE
MOUNTAINS AND FOOTHILLS THESE DAYS. A COLD FRONT IS EXPECTED TO
MOVE THROUGH MONDAY BRINGING SURFACE HIGH PRESSURE. THIS WILL
COOL HIGH TEMPERATURES INTO THE 90S F MONDAY AND 80S TO LOW 90S F
TUESDAY.
MIDDLE TO LATE NEXT WEEK, ENSEMBLES ARE IN GOOD AGREEMENT THAT
UPPER LEVEL RIDGING WILL BUILD BACK AND RETURN MONSOONAL MOISTURE.
THE EXACT NATURE IN WHICH THE RIDGE BUILDS BACK IS UNCERTAIN,
THOUGH THERE IS GENERAL AGREEMENT THAT MUCH ABOVE AVERAGE
TEMPERATURES WILL NOT RETURN. THERE IS HIGHER CONFIDENCE THAT
MONSOONAL MOISTURE WILL BRING THE RETURN OF DAILY SHOWER AND
THUNDERSTORM CHANCES. TORGERSON
AVIATION
12Z UPDATE...
POCKET OF SHOWERS LINGERING ACROSS FAR EAST CENTRAL MT THROUGH 15Z
THIS MORNING IS NOT EXPECTED TO REDUCE FLIGHT CATEGORIES BELOW
VFR. A FEW LIGHT SHOWERS NEAR KLVM THIS MORNING MAY PRODUCE
ERRATIC SFC WIND TO 25KTS. OTHERWISE, EXPECT ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TODAY, MAINLY AFTER 21Z. SOME
THUNDERSTORMS MAY PRODUCE TORRENTIAL RAINFALL AND VERY STRONG
ERRATIC SFC GUSTS TO 50 KTS. IFR CONDITIONS ARE POSSIBLE UNDER
INTENSE RAINFALL. BT
POTENTIAL TS TIMING :
KLVM: 17Z-03Z
KBIL: 22Z-04Z
KSHR: 20Z-04Z
KMLS: 03Z-07Z
PRELIMINARY POINT TEMP/POPS
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 096 068/097 068/097 066/091 066/089 065/091 066/091
1/B 61/B 21/U 10/U 11/B 22/T 33/T
LVM 092 057/094 057/095 057/091 057/086 056/089 057/089
4/T 81/B 20/U 00/U 23/T 35/T 54/T
HDN 098 067/097 066/098 064/092 063/090 063/092 064/092
1/B 51/B 21/U 20/U 11/B 21/B 33/T
MLS 097 070/100 069/099 066/091 063/088 064/091 065/093
3/W 62/W 21/U 10/U 01/B 21/B 22/W
4BQ 096 070/099 069/097 066/091 064/087 064/088 064/089
2/B 32/W 32/T 20/U 22/W 42/W 33/T
BHK 095 065/097 066/098 062/090 058/085 058/087 059/090
3/T 33/T 21/U 10/U 00/B 31/B 12/T
SHR 095 062/095 062/094 060/091 059/088 059/088 059/087
3/T 32/T 24/T 21/U 24/T 45/T 45/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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